An adaptive packet scheduling algorithm for efficient downlink bandwidth allocation in UWB based wireless infrastructure networks

Abstract

A short range wireless infrastructure network, in which multiple UWB (ultra-wideband) WPANs are interconnected, is envisioned to be an important platform for various large scale mobile computing applications. It has been suggested that traditional packet scheduling algorithms used in cellular networks can be used for UWB based short-range networks. Unfortunately, these existing algorithms, e.g., HSDPA, cannot properly balance the conflicting goals of maximizing bandwidth efficiency while providing adequate fairness to users. Recently, an efficient scheme called MTA-ISIR is suggested and is found to be effective under several practical scenarios. Nevertheless, we find that there are still some drawbacks in the MTA-ISIR algorithm. In this paper, we propose two new approaches in which the power level threshold used for handling the fairness is dynamically adjusted for different traffic models. Our first approach is based on the "opportunistic scheduling" concept which enables the scheduler to optimize the bandwidth efficiency without sacrificing fairness. The second approach makes use of the consecutive packet lengths to prioritize users when assigning time slots. Simulation results indicate that the proposed methods outperform MTA-ISIR under a wide range of parameters. © 2007 Elsevier B.V. All rights reserved.